Apparatus to obtain fresh water from moisture containing air

ABSTRACT

An elongated flexible tube has its upper end attached to a lighter-than-air balloon, preferably in the form of a non-rigid air ship (blimp), the length of the tube being sufficiently great to extend from about ground level to a temperature zone having a climatic condition in which the temperature or moisture distribution of the atmosphere is sufficiently different from that at ground level to permit, either, condensation of moisture as moisture-containing atmosphere is conducted upwardly into the tube or introduction of seed crystals, such as silver iodide, into the atmosphere to cause precipitation. In the first case, the tube is preferably terminated at its lower end at an opening spaced a short distance above a large body of water, such as an ocean, and maintained on floats or pontoons located in the subtropical or tropical regions, moisture-laden air from the ocean being drawn into the tube so that the water only will condense on the tube walls, at the upper atmospheric reaches thereof, to be drawn off and collected. In the second case, when seed crystals are to be introducted, the tube is preferably mounted on an automotive vehicle for wide dispersion of seed crystals.

[76] Inventor:

United States Patent 1 Bel Hamri APPARATUS TO OBTAIN FRESH WATER FROMMOISTURE CONTAINING AIR Bernard Andre Bel Hamri, Immeuble lHorizon, Ave.Delafosse, Abidjan PB: 675, Ivory Coast 22 Filed: Jan. 26, 1972 211Appl. No.: 220,869

[ 1 July 31, 1973 Primary Examiner-Meyer Perlin AssistantExaminer-Ronald C. Capossela Attorney-Robert D. Flynn, Stephen H.Frishauf et a1.

[57] ABSTRACT An elongated flexible tube has its upper end attached to alighter-than-air balloon, preferably in the form of a non-rigid air ship(blimp), the length of the tube being sufficiently great to extend fromabout ground level to a temperature zone having a climatic condition inwhich the temperature or moisture distribution of the atmosphere issufficiently different from that at ground level to permit, either,condensation of moisture as moisture-containing atmosphere is conductedupwardly into the tube or introduction of seed crystals, such as silveriodide, into the atmosphere to cause precipitation. In the first case,the tube is preferably terminated at its lower end at an opening spaceda short distance above a large body of water, such as an ocean, andmaintained on floats or pontoons located in the sub-tropical or tropicalregions, moisture-laden air from the ocean being drawn into the tube sothat the water only will condense on the tube walls, at the upperatmospheric reaches thereof, to be drawn off and collected. 1n thesecond case, when seed crystals are to be introducted, the tube ispreferably mounted on an auto motive vehicle for wide dispersion of seedcrystals.

9 Claims, 4 Drawing Figures APPARATUS TO OBTAIN FRESH WATER FROMMOISTURE CONTAINING AIR The present invention relates to apparatus toextract fresh water from salt water, or from clouds in hot climates, andmore particularly to generate fresh water in dry climatic zones whichare adjacent large bodies of water, such as the ocean.

It has previously been proposed to utilize sea water and, by variousprocesses of desalinization, to extract fresh water which can be used inhuman or animal consumption, or for agriculture. Most of these processesutilize evaporation and distillation techniques. Other processes includesteps in which the water is frozen, the ice being essentially salt-freeso that, when the ice is again melted, fresh water is obtained. Most ofthese processes have disadvantages in that the residual salts aredifficult to eliminate, cause trouble with the apparatus, andsubstantially raise the price of the fresh water which is produced sothat the cost of the fresh water quickly reaches a prohibitive level.Additionally, the installation costs of the apparatus and machinery ishigh so that generation of fresh water from saline sea water isrestricted to few and selected installations.

It is an object of the present invention to provide an apparatus toobtain fresh water from moisture laden air which does not requirecomplicated apparatus, and in which such devices and apparatus as arenecessary are inexpensive, readily mobile, and do not require specialinstallations nor auxiliary or support apparatus of high technology.

SUBJECT MATTER OF THE PRESENT INVENTION Briefly, moisture-laden air isintroduced into an elongated flexible tube, having its bottom openingat, or close to ground level and supported, for example by pontoons orthe like, above a body of water such as the ocean. The top of the tubeis held at great altitude, elevated by a balloon or the like which islighter than air, such as a non-rigid air ship. At sufficient altitudes,the temperature at the upper end of the tube will be much colder thanthat at the surface of the sea. Moistureladen air, from the sea surfaceis sucked into the tube by fans or blowers, or the like. Only littlepower is necessary in order to introduce moisture-laden air, for examplefrom the bottom ofa tarpaulin, or the like of sufficient extent, forexample of hundred square meters, or more, into the bottom of the tube.The air, saturated with water vapor is drawn upwardly along the lengthof the tube until it arrives at a height where the outside climaticconditions are such that the temperature is sufficiently low and thewater in suspension can condense naturally along the walls of the tube,to fall downwardly along the inner tube walls into a reservoir providedon the pontoons to hold the fresh water. Saline residues are practicallyeliminated since the water vapor above sea level contains but littlesalt, and the water which is received in the reservoir is fresh waterwith hardly any mineral or saline content.

In climatic zones where large bodies of water are not present, forexample at the interior of deserts, but where from time to timemoisture-laden air, that is, clouds pass by, the same apparatus, withminor modifications, can be used to extract the fresh water not from abody of water at ground level, but rather, from a body of moisture vaporin the air. Cloud seeding crystals are introduced into the tube at thebottom, the upper level of the tube being held by the balloon or thelike at cloud level, so that the cloud seeding crystals can beintroduced directly into the cloud to cause fresh water, that is,moisture to precipitate and fall in the form of rain. Costs for aircraftfor cloud seeding, and the like, are therefore eliminated. The tubeitself can be mounted on a vehicle, such as a truck, for mobility andfor passage beneath the cloud formation to increase the extent of cloudseeding possible, and thus the recuperation of moisture from theatmosphere.

The invention will be described by way of example with reference to theaccompanying drawings, wherein:

FIG. 1 is a general schematic view illustrating the application of theinvention to extract moisture from water vapor existing just above thesurface of the ocean;

FIG. 2 is a fragmentary, schematic view, to a different scale,illustrating details of the apparatus;

FIG. 3 is a view of the apparatus as applied to cloud seeding, mountedon a vehicle;

and FIG. 4 is a fragmentary schematic view illustrating portions of theapparatus of FIG. 3.

The apparatus of FIGS. 1 and 2 comprises a blimp, or non-rigid air ship1 having wind-responsive rudders 1 at the rear end thereof, so that theblimp will turn towards the wind. The air ship itself is located at theupper end of a flexible tube 2, having its opening directed towards therear of the blimp l. The blimp and the tube can be formed, at the upperend, as a single molded plastic or rubberized structure, or connected orattached to each other by any means well known in the art; additionalattachment cables or guy wires can be used, and have been left off fromthe drawing for simplicity.

The upper opening of the flexible tube 2, directed towards the rearportion 15 of the blimp I has the effect that winds blowing against theblimp will have the tendency to establish a vacuum at the aft end of theblimp with respect to its forward nose, and thus to provide suction atthe exit opening of tube 2. The lower end of tube 2 has an injectiontube 8 for moisture-laden air therein (FIG. 2). Injection element 8 isconnected to the outlet ofa blower or fan 3 which has an inlet 12capable of taking in moisture-laden air, located close to the surface ofthe ocean 16, at a location at which evaporation of water is intense.The moisture saturated air is directed by blower 3 upwardly, indirection of arrow 9, and passes through the interior of the tubetowards the top opening thereof. As the moisture-saturated air reachesan altitude which is sufficiently high so that the outside temperaturebecomes sufficiently less than the temperature at the surface of theocean 16, the moisture in suspension in the vapors being conducted upthe tube will condense at the inner walls of the tube 2 in order to fallback under gravity as seen by arrows 10. The condensed liquid from theinner walls of the tube is caught in a recovery vessel 14, attached to ahollow inlet tube 11. Outlet valve 14 from recovery vessel 4 can then beused to tap off fresh water.

In order to prevent obstruction of tube 2 by condensed water, asindicated by arrows 10, and to prevent decrease of air flow injected bythe blower apparatus 3, a flap valve 13 is provided at the lower openingof the tube 11. The flap valve, and the blower 3 are alternatelycyclically operated, for example by a timer or cycling apparatus (notshown, and well known in the art). Upward introduction of moisture-ladenair is carried out during a first phase during which valve 13 is closed.This prevents dry air, or air not taken directly from above the oceansurface to be introduced through tube 11 into tube 2. In a second phase,the blower 3 is stopped for a time sufficiently great to permitcondensed water to run down the inside walls of the tube 2, while valve13 is open.

The apparatus is sustained on pontoons 5, located on a suitableframework. The top of the framework is covered, for example by tarpaulinor other essentially airtight covering 6. The airtight covering 6 ismaintained a short distance above sea level.

The lateral extent of the non-pervious covering 6, on pontoons may be ahundred square meters or more; the eventual size will depend on theflexibility of the framework in the light of wave action, storms and thelike to be expected. The greater the surface covered by the covering 6,the greater the inflow of moisturecontaining air into tube 2 and thusthe greater the recovery of fresh water.

The apparatus has the advantage that it can be located at any place,where desired, along the shore. Preferably, winching apparatus or thelike (not shown) to control the air ship 1 is also installed on thepontoons, together with guy and support cables. The water caught inreservoir 4 is completely free of saline residue, or any othercontamination which may have been present in the ocean water itself. Theenergy of sunlight, and ambient temperature is utilized to effectevaporation of the water, and cooling of the moisturecontaining air iscarried out by making use of naturally occurring temperaturedifferences, so that no additional power requirements for operation ofthe apparatus during water recovery are needed. Since the water obtainedis taken from moisture-containing air, the water in reservoir 4 willhave practically the characteristics of distilled water.

The apparatus as described can be located not only on the ocean, butalso on other large bodies of water, located in climatic zones whereevaporation of water occurs at a high rate.

The vapor contained in the air close to the ocean can be condensed inthe form of droplets; there are two requirements in order to obtaincondensation: air which is saturated, and presence of condensation coresor surfaces.

The effect of saturation and condensation is usually obtained by coolingof the air; air which is cooled can be saturated with a moisturequantity which is less than that when the air is hot. For example, onecubic meter of air which contains 1 l g of water vapor at a temperatureof 25 C is not saturated; a quantity of ll g of water vapor in l in willsaturate at C. Thus, by cooling, condensation of the water can beobtained and the water recuperated.

Natural spontaneous evaporation of free air is most active when thesurface of the liquid is great; the temperature of the liquid to beevaporated, as well as the surrounding air temperature is high; the airis substantially dry; and the air is not frequently renewed in otherwords, there is little wind. These conditions are present in many aridand dry countries bordering oceans; if sufficient air flow anddifference in temperature due to the length of tube 2 can be obtained,then the additional blower 3 need provide but little output, or may evenbe completely unnecessary. It is, however,

desirable to have a substantially great volume of air pass through tube2.

The length of the tube 2 depends on the climatic and environmentalconditions and may, typically, rise to 3000 m, or more, that is, to aregion in which the temperature has dropped sufficiently forcondensation of moisture. It is known that, on the average, atemperature drop of 6.5C per 1000 meters is usual. Air, therefore, underrapid cooling will saturate at a given altitude, and water vaporcontained in the air will condense in the form of droplets which willfall down to ground level under their own weight. These droplets maythus run down at the inner walls of the tube, for collection in recoveryvessel 4, or they may fall down separately in the form of rain.

Fresh water can be obtained not only from water vapor contained in airclosely adjacent a surface of a body of water, such as closely above theocean, but also from clouds, by utilizing the apparatus to introduce alarge quantity of cloud seeding crystals into a cloud. Such cloudseeding is well known, and usually utilizes silver iodide crystals, infine dispersions, introduced into cloud masses. I

The modification of the apparatus merely requires substitution of thecollection vessel 4, for fresh water, by an injection element 17 throughwhich silver iodide crystals are introduced into tube 2, to be blownupwardly by blower 3. Rather than mounting the structure on pontoons,for support over a body of water, the apparatus is now mounted on atruck 19, or other vehicular, movable support, such as railway rollingstock. The silver iodide reservoir 17 has an injection nozzle 18 whichextends into tube 11. The output of the nozzle 18 can be controlled, bycontrolling the nozzle. Upon operation of the blower, silver iodide willbe atomized and injected, upwardly through the tube, into clouds at highaltitude, to which the upper end of the tube has been brought bymovement of vehicle 19. The blimp l is controlled in the same manner asbefore, for example by additional guy wires or cables (not shown) andinjection of the atomized silver iodide crystals again is downstreamwith respect to the aerodynamic shape of blimp l. The entire apparatusis lightweight, easy to handle, and can be placed or relocated asdesired; for extensive cloud seeding, the vehicle 19 can be moved overthe ground surface during the seeding; for longer displacement, overgreater distances, tube 2 can be hauled in an blimp 1 collapsed, thetotal volume of the blimp and the tube being easily storable on vehicle19 itself. Other crystals than silver iodide can be used although silveriodide crystals have been found effective in this field, in order toobtain rain water from clouds. Great volumes of cloud masses can beseeded in short time intervals, diffusion of the seed material beingfacilitated and indeed ensured by bending the outlet of tube 2 towardsthe aft of blimp l.

The apparatus may thus be used in various applications without essentialmodification; in one application, to have the upper end of the flexibletube 2 introduced into clouds for cloud seeding, and on the other, tohave the lower end of the tube placed close to a source ofmoisture-laden air, such as above ocean surfaces, the apparatus itselfremaining essentially unchanged but being merely mounted on differentsupports, above ground or above water.

The tube 2 can be of various materials, for example matching that of theblimp l; or it may be of fiberglass,

nylon, other man-made fabrics, rubberized or plasticized to provide anessentially water and air impervious enclosure having, however,sufficient light weight to be readily carried by blimp 1. Stiffeningrings, or the like, may be located at intervals along the tube 2 toprevent collapse of the tube under wind stresses. The tube 2 can beessentially cylindrical, or slightly conical, tapering upwardly and canbe somewhat ridged, at least internally, or formed with beads tofacilitate condensation of moisture on the inside of the tube.

Various changes and modifications may be made within the inventiveconcept. I claim:

1. Apparatus to obtain fresh water from moisturecontaining aircomprising an elongated flexible tube; lighter-than-air balloon meansattached to the upper end of the elongated tube, the lower end of thetube being located at essentially ground level, the length of the tubebeing sufficient to extend from a temperature zone, at ground level, toa zone of climatic conditions including termperature or moisturedistribution in the air which is different from the climatic conditionsat ground level and where the temperature is less than at ground level;the balloon means having sufficient lift to hold the tube extended fromground level to said zone having lesser temperature; means generating anupdraft in the tube; and means in fluid communication with the tube tocollect water condensing at the side walls of the tube and running alongthe tube walls, by gravity. 2. Apparatus according to claim 1, whereinthe lower end of the tube is located above a body of water;

means are provided funnelling moisture-laden air from above the surfaceof the body of water into the lower end of the tube, the tube being ofsufficient length to reach to a height at which the ambient temperatureoutside of the tube is sufficient for condensation of moisture of theair in the tube at the sidewalls of the tube. 3. Apparatus according toclaim 2, including float means supporting the lower end of the tubeabove the water;

and said means funnelling the air into the tube comprising directingbaffle means spaced from above the surface of the body of water andhaving means extending into said tube to direct moisture-laden air intothe inlet of the tube.

4. Apparatus according to claim 3, wherein the air directing bafflescomprise sheet-like flexible materials; pontoons are provided supportingsaid sheet-like flexible material above the surface of the ocean.

5. Apparatus according to claim 4, wherein the area of said sheet-likematerial is at least in the order of m 6. Apparatus according to claim2, including forced air circulation means introducing moisture-laden airfrom above the surface of the body of water into the tube and blowingthe air upwardly therein.

7. Apparatus according to claim 6, including valve means in said tubeselectively effecting connection at the lower end of the tube,cyclically, with 1. said forced air circulation means to drawmoistureladen air into the tube and circulate it upwardly thereof; and

2. the condensate collection means, said forced air circulation meansbeing stopped during at least part of the cycle during which the valveestablishes communication with the condensate collection means.

8. Apparatus according to claim 1, wherein the lighter-than-air balloonmeans are in streamlined form;

and the upper end of the tube is arranged on the lighter-than-airballoon means in such a manner that winds blowing against the balloonmeans create a partial vacuum adjacent the upper end of the tube toassist in causing a draft within the tube.

9. Apparatus according to claim 1, wherein the length of the tube is inthe order of several thousands of meters.

1. Apparatus to obtain fresh water from moisture-containing air comprising an elongated flexible tube; lighter-than-air balloon means attached to the upper end of the elongated tube, the lower end of the tube being located at essentially ground level, the length of the tube being sufficient to extend from a temperature zone, at ground level, to a zone of climatic conditions including termperature or moisture distribution in the air which is different from the climatic conditions at ground level and where the temperature is less than at ground level; the balloon means having sufficient lift to hold the tube extended from ground level to said zone having lesser temperature; means generating an updraft in the tube; and means in fluid communication with the tube to collect water condensing at the side walls of the tube and running along the tube walls, by gravity.
 2. the condensate collection means, said forced air circulation means being stopped during at least part of the cycle during which the valve establishes communication with the condensate collection means.
 2. Apparatus according to claim 1, wherein the lower end of the tube is located above a body of water; means are provided funnelling moisture-laden air from above the surface of the body of water into the lower end of the tube, the tube being of sufficient length to reach to a height at which the ambient temperature outside of the tube is sufficient for condensation of moisture of the air in the tube at the sidewalls of the tube.
 3. Apparatus according to claim 2, including float means supporting the lower end of the tube above the water; and said means funnelling the air into the tube comprising directing baffle means spaced from above the surface of the body of water and having means extending into said tube to direct moisture-laden air into the inlet of the tube.
 4. Apparatus according to claim 3, wherein the air directing baffles comprise sheet-like flexible materials; pontoons are provided supporting said sheet-like flexible material above the surface of the ocean.
 5. Apparatus according to claim 4, wherein the area of said sheet-like material is at least in the order of 100 m2.
 6. Apparatus according to claim 2, including forced air circulation means introducing moisture-laden air from above the surface of the body of water into the tube and blowing the air upwardly therein.
 7. Apparatus according to claim 6, including valve means in said tube selectively effecting connection at the lower end of the tube, cyclically, with
 8. Apparatus according to claim 1, wherein the lighter-than-air balloon means are in streamlined form; and the upper end of the tube is arranged on the lighter-than-air balloon means in such a manner that winds blowing against the balloon means create a partial vacuum adjacent the upper end of the tube to assist in causing a draft within the tube.
 9. Apparatus according to claim 1, wherein the length of the tube is in the order of several thousands of meters. 